CN104112799A - Lattice-matched LED epitaxial structure and preparation method thereof - Google Patents

Abstract

The invention relates to a lattice-matched LED epitaxial structure and a preparation method thereof. The invention relates to a nitride light-emitting diode epitaxial structure whose nucleating layer, undoped layer, n type layer, luminous layer and p type layer all have polarization matching and a preparation method, and belongs to the technical field of photoelectronics. The epitaxy structure is provided with a substrate, a AlxGa(1-x)-yInyN nucleating layer, an undoped AlxGa(1-x)-yInyN layer, n type doped AlxGa(1-x)-yInyN layer, a multi-quantum well luminous layer formed by a InaGa(1-a)N well layer and a AlxGa(1-x)-yInyN barrier layer, and a p type doped AlxGa(1-x)-yInyN layer in sequence from bottom to top. Compared with a traditional structure, the epitaxial structure adopts quaternary AlxGa(1-x)-yInyN material matched with luminous layer well material from the nucleating layer to a luminous layer interval and P type doped layer, thereby eliminating a piezoelectric polarization effect between well and barrier layers in the luminous layer, and improving internal quantum luminous efficiency of the LED.

Description

LED epitaxial structure of a kind of Lattice Matching and preparation method thereof

Technical field

The present invention relates to a kind of gallium nitride based light emitting diode, more specifically relate to a kind of from nucleating layer, undoped layer, N-shaped layer, luminescent layer and the p-type layer iii-nitride light emitting devices that all tool polarization is mated.

Background technology

LED industry development was rapid in recent years, and centering, large power white light LED demand get more and more.Yet in, large power white light LED illumination will enter huge numbers of families, also needs further to improve luminosity and improving luminous efficiency.

The reason that affects blue light brightness mainly contains the following aspects: 1, be difficult to obtain high concentration hole; 2, polarized electric field is more intense, enables band and bends, and causes electronics spatially not exclusively to overlap with the wave function in hole, thereby has reduced charge carrier radiation recombination speed, makes the internal quantum efficiency of device low; 3, between substrate and epitaxial loayer, have larger lattice mismatch, crystal mass is poor.

Traditional LED epitaxial structure, referring to Fig. 1, is followed successively by from top to bottom: 1, Sapphire Substrate; 2, GaN nucleating layer; 3, Doped GaN layer not; 4, N-shaped Doped GaN layer; 5, multiple quantum well light emitting layer (InGaN trap and GaN build); 6, p-type Doped GaN layer.

But there is following shortcoming in said structure: first, owing to having larger lattice mismatch between trap layer and base layer, can produce stronger internal electric field, impel band curvature; Secondly, because the effective mass of electronics is low weight, there will be the phenomenon of overflow; Then be between last base layer and P type electronic barrier layer, to have larger energy level difference, the injection in restriction hole.

CN103022290A provides a kind of LED epitaxial structure with quaternary InAlGaN and preparation method thereof, it is characterized in that inserting InAlGaN stress release layer between the GaN layer of N-shaped doping and multiple quantum well light emitting layer, but the thickness of this layer is 40nm-50nm, can not effectively slow down the GaN layer of N-shaped doping and the lattice strain between multiple quantum well light emitting layer.

Min-Ho Kim proposes to replace respectively base and the electronic barrier layer in MQW with the quaternary AlInGaN of different components, slowed down greatly the phenomenon that under large electric current, luminous efficiency declines, consult document Min-Ho Kim, Martin F.Schubert, Qi Dai, Jong Kyu Kim, and E.Fred Schubert, " Origin of efficiency droop in GaN-based light-emitting diodes " Applied Physics Letters, 91,2007,183507.But in this structure, there is no to consider to be present in the GaN layer of N-shaped doping and the lattice strain between the lattice strain between multiple quantum well light emitting layer, electronic barrier layer and p-type gallium nitride layer.The existence of these strains all can have influence on the injection efficiency in electronics and hole.

Guangyu Liu etc. replace part GaN base with the AlGaInN of broad-band gap, have reduced the overflow of electronics.List of references, Guangyu Liu, Jing Zhang, Chee-Keong Tan, and Nelson Tansu, " Efficiency-Droop Suppression By Using Large-Bandgap AlGaInN Thin Barrier Layers in InGaN Quantum-Well Light-emitting diodes " IEEE Photonics Journal, 5 (2), 2013,2201011.Although AlGaInN mates completely with GaN barrier material lattice, do not realize the Lattice Matching of InGaN trap material and barrier material, make still to exist the lattice strain at trap and base.

Due to III group-III nitride quaternary material Al _xga _1-x-yin _yn has two tunable component parameter x and y, and ternary compound has higher flexibility relatively, can be by these two component parameter are optimized and are obtained in order to obtain certain specific material parameter.

The band gap of quaternary nitride and lattice constant can be divided effectively and be regulated by four-tuple.

a(Al _xGa _1-x-yIn _yN)＝xa _AlN+ya _InN+(1-x-y)a _GaN

Wherein,

a _AlN＝0.3112nm,a _InN＝0.3548nm,a _GaN＝0.3189nm

$E_g\left({\mathrm{Al}}_{x}G{a}_{1-x-y}I{n}_{y}N\right)=\frac{\mathrm{xyEg}\left(\mathrm{AlInN}\right)+\mathrm{yzEg}\left(\mathrm{InGaN}\right)+\mathrm{xzEg}\left(\mathrm{AlGaN}\right)}{\mathrm{xy}+\mathrm{yz}+\mathrm{zx}}$

Wherein,

E _g(AlInN)＝uE _g(InN)+(1-u)E _g(AlN)-u(1-u)b(AlInN)

E _g(InGaN)＝vE _g(GaN)+(1-v)E _g(InN)-v(1-v)b(InGaN)

E _g(AlGaN)＝wE _g(GaN)+(1-w)E _g(AlN)-w(1-w)b(AlGaN)

$u=\frac{1-x+y}{2},v=\frac{1-y+x}{2},w=\frac{1-x+z}{2}.$

Summary of the invention

The object of type of the present invention is to provide a kind of nitride light-emitting diode structure and manufacture method of the coupling that polarizes, further to improve the luminous efficiency of LED epitaxial wafer.

The LED epitaxial structure that the invention provides a kind of Lattice Matching, comprising: substrate, on described substrate, is disposed with Al from the bottom to top _xga _1-x-yin _yn nucleating layer, unadulterated Al _xga _1-x-yin _ythe Al of N layer, N-shaped doping _xga _1-x-yin _yn layer, In _aga _1-an trap layer and Al _xga _1-x-yin _yn builds the multiple quantum well light emitting layer of layer formation and the Al of p-type doping _xga _1-x-yin _yn layer; The Al of each layer _xga _1-x-yin _ythe trap layer In of the lattice constant of N and multiple quantum well light emitting layer _aga _1-athe lattice constant of N is identical, the Al of each layer _xga _1-x-yin _ythe band gap width of N is greater than the trap layer In of multiple quantum well light emitting layer _aga _1-athe band gap width of N.

Wherein, described nucleating layer is Al _xga _1-x-yin _yn, its thickness is 30nm-50nm, x span: 0.5≤x≤0.65, y span: 0.2≤y≤0.4;

The described Al that is not doped to _xga _1-x-yin _yn, its thickness is 1 μ m-2.5 μ m, x span: 0.5≤x≤0.65, y span: 0.2≤y≤0.4;

Described N-shaped doped layer is Al _xga _1-x-yin _yn, its thickness is 1 μ m-2.5 μ m, x span: 0.5≤x≤0.65, y span: 0.2≤y≤0.4;

The Al of described N-shaped doping _xga _1-x-yin _yn layer consists of high doped regions two parts, the heavily doped layer of the 1 μ m-2.2 μ m that first grows, and the low doped layer of rear growth 0.1 μ m-0.3 μ m, the Si doping content of heavily doped layer is 8 * 10 ¹⁸cm ^-3-2 * 10 ¹⁹cm ^-3, the Si doping content of low doped layer is 1 * 10 ¹⁷cm ^-3-3 * 10 ¹⁷cm ^-3; Described multiple quantum well light emitting layer is by the spaced apart In in 1-15 cycle _aga _1-an trap layer and Al _xga _1-x-yin _yn builds the stacked composition that adds; Its gross thickness is 10nm-300nm; A span: 0.1≤a≤0.25, x span: 0.5≤x≤0.65, y span: 0.2≤y≤0.4;

Described p-type doped layer is Al _xga _1-x-yin _yn, its thickness is 100nm-250nm, x span: 0.5≤x≤0.65, y span: 0.2≤y≤0.4; Mg doping content is 5 * 10 ¹⁹cm ^-3--1 * 10 ²⁰cm ^-3;

For achieving the above object, the present invention also provides a kind of iii-nitride light emitting devices manufacture method of the coupling that polarizes, and comprises following step:

1) Sapphire Substrate is placed under hydrogen atmosphere, is heated to 1050 ℃-1150 ℃ and keep 5min-10min, to remove the H of substrate surface ₂o and O ₂;

2) under hydrogen atmosphere condition, regulate temperature that substrate layer is heated to 450 ℃-600 ℃, pressure 100Torr-500Torr, keeps 5min-10min, take TMGa as Ga source, take NH3 as N source, take TMAl as Al source, take TMIn as In source, starts the Al that grows _xga _1-x-yin _yn nucleating layer, thickness is 30nm-50nm; Then regulate temperature to 750 in MOCVD reative cell ℃-860 ℃, pressure 100Torr-500Torr, keeps 5min-10min, makes described Al _xga _1-x-yin _yn nucleating layer recrystallization; Then regulate temperature to 750 in MOCVD reative cell ℃-860 ℃, unadulterated Al grows _xga _1-x-yin _ythe Al of N layer 1 μ m-2.5 μ m, N-shaped doping _xga _1-x-yin _yn layer 1 μ m-2.5 μ m;

3) Al of described N-shaped doping _xga _1-x-yin _yn layer consists of high doped regions two parts, the heavily doped layer of the 1 μ m-2.2 μ m that first grows, and the low doped layer of rear growth 0.1 μ m-0.3 μ m, the Si doping content of heavily doped layer is 8 * 10 ¹⁸cm ^-3-2 * 10 ¹⁹cm ^-3, the Si doping content of low doped layer is 1 * 10 ¹⁷cm ^-3-3 * 10 ¹⁷cm ^-3;

4) Al adulterating at N-shaped _xga _1-x-yin _ythe multiple quantum well light emitting layer of growing on N layer: multiple quantum well layer is InGaN trap and the thick Al of 8nm-20nm that 1-15 repetition period and thickness are respectively 2nm-10nm thickness _xga _1-x-yin _yn builds.Growth Al _xga _1-x-yin _ythe preparation condition that N builds is that the temperature in MOCVD reative cell is adjusted to 750 ℃-860 ℃, and pressure 100Torr-500Torr, take TMGa as Ga source, with NH ₃for N source, take TMAl as Al source, take TMIn as In source, growth Al _xga _1-x-yin _yn builds layer; The preparation condition of growing InGaN trap layer is that the temperature in MOCVD reative cell is adjusted to 750 ℃-860 ℃, and pressure 100Torr-500Torr closes TMAl source simultaneously, take TMGa as Ga source, with NH ₃for N source,, take TMIn as In source, growth In _aga _1-an trap layer;

5) regulate temperature to 750 in MOCVD reative cell ℃-860 ℃, growing p-type doped layer Al on multiple quantum well light emitting layer _xga _1-x-yin _yn, thickness is 100nm-300nm, Mg doping content is 5 * 10 ¹⁹cm ^-3--1 * 10 ²⁰cm ^-3;

6) by above-mentioned steps 5) product that obtains is placed in the 15min-30min that anneals under the nitrogen atmosphere of 650 ℃-750 ℃.

The present invention has following beneficial effect:

1, the present invention is by starting from nucleating layer until MQW luminescent layer all adopts Al _xga _1-x-yin _yn component, makes the In of itself and luminescent layer _aga _1-an trap material lattice constant is identical or approaching, has following advantage, and the first, due to In _aga _1-athe lattice constant of N material, between GaN and Sapphire Substrate, has reduced lattice mismatch, therefore can improve crystal growth quality, and dislocation density is reduced, and improves radiation recombination efficiency and the interior quantum luminous efficiency of LED.The second, due to the Al of MQW luminescent layer _xga _1-x-yin _yn builds and In _aga _1-an trap material lattice constant is identical or approaching, can effectively reduce and to band edge trigonometric ratio and the radiation wavelength Red Shift Phenomena eliminating the piezoelectric polarization effect that produces in quantum well and cause, and can make the phenomenon that under large electric current, luminous efficiency declines effectively slow down.

2, the present invention adopts Al by p-type layer _xga _1-x-yin _yn component material, forms and mates on lattice with MQW structure above on the one hand, has reduced lattice strain, on the other hand due to Al _xga _1-x-yin _yn grows 750 ℃ of-860 ℃ of temperature ranges, and 980 ℃ of-1100 ℃ of high growth temperature environment facies ratios with conventional p-type GaN, can reduce the thermal strain of MQW structure, the crystal mass of protection MQW luminescent layer.

Accompanying drawing explanation

By describing in more detail exemplary embodiment of the present invention with reference to accompanying drawing, above and other aspect of the present invention and advantage will become and more be readily clear of, in the accompanying drawings:

Fig. 1 tradition LED structural diagrams intention;

Fig. 2 LED epitaxial structure of the present invention schematic diagram.

In Fig. 1,1, Sapphire Substrate; 2, GaN nucleating layer; 3, Doped GaN layer not; 4, N-shaped Doped GaN layer; 5, multiple quantum well light emitting layer (In _aga _1-an trap and GaN build); 6, p-type Doped GaN layer;

In Fig. 2,1, Sapphire Substrate; 2, Al _xga _1-x-yin _yn nucleating layer; 3, doped with Al not _xga _1-x-yin _yn layer; 4, N-shaped doped with Al _xga _1-x-yin _yn layer; 5, multiple quantum well light emitting layer (In _aga _1-an trap and Al _xga _1-x-yin _yn builds); 6, p-type doped with Al _xga _1-x-yin _yn layer.

Embodiment

Hereinafter, now with reference to accompanying drawing, the present invention is described more fully, various embodiment shown in the drawings.Yet the present invention can implement in many different forms, and should not be interpreted as being confined to embodiment set forth herein.On the contrary, it will be thorough with completely providing these embodiment to make the disclosure, and scope of the present invention is conveyed to those skilled in the art fully.

Hereinafter, exemplary embodiment of the present invention is described with reference to the accompanying drawings in more detail.

Embodiment 1

A LED epitaxial structure for Lattice Matching, comprises on substrate layer 1 it being that thickness is the Al of 25nm successively _0.51ga _0.18in _0.31n nucleating layer 2, thickness are the not doped with Al of 1.2 μ m _0.51ga _0.18in _0.31n layer 3, thickness are the Si doped with Al of 1.5 μ m _0.51ga _0.18in _0.31the Mg doped with Al that N layer 4, multiple quantum well light emitting layer 5 and thickness are 200nm _0.51ga _0.18in _0.31n layer 6; Described multiple quantum well light emitting layer 5 is that 9 repetition periods and thickness are respectively the In that 3nm is thick _0.2ga _0.8the Al that N trap layer and 12nm are thick _0.51ga _0.18in _0.31n builds layer and forms; The Si doped with Al of 1.5 described μ m _0.51ga _0.18in _0.31n layer 4 is that the low doped layer by the heavily doped layer of 1.3 μ m and 0.2 μ m forms, and the Si doping content of heavily doped layer is 8 * 10 ¹⁸cm ^-3, the Si doping content of low doped layer is 2 * 10 ¹⁷cm ^-3.

Embodiment 2

The preparation method of LED structure described in embodiment 1, concrete steps are as follows:

1, Sapphire Substrate is placed under hydrogen atmosphere, is heated to 1080 ℃ and keep 5min, to remove the H of substrate surface ₂o and O ₂;

2, under hydrogen atmosphere condition, regulate temperature that substrate layer is heated to 540 ℃, pressure 500Torr, keeps 5min, take TMGa as Ga source, take NH3 as N source, take TMAl as Al source, take TMIn as In source, starts the Al that grows _0.51ga _0.18in _0.31n nucleating layer, thickness is 30nm; Then regulate the temperature to 860 ℃ in MOCVD reative cell, keep 10min, make described Al _0.51ga _0.18in _0.31n nucleating layer carries out recrystallization;

3) keep the temperature to 860 ℃ in MOCVD reative cell, pressure 350Torr, unadulterated Al grows _0.51ga _0.18in _0.31the Al of N layer 1.2 μ m, N-shaped doping _0.51ga _0.18in _0.31n layer 1.5 μ m.The Al that wherein N-shaped adulterates _0.51ga _0.18in _0.31n layer portions, the Si doping content of first growing is 8 * 10 ¹⁸cm ^-3the thick heavily doped layer of 1.3 μ m, rear growth Si doping content is 2 * 10 ¹⁷cm ^-3the thick low doped layer of 0.2 μ m;

4) Al adulterating at N-shaped _0.51ga _0.18in _0.31the multiple quantum well light emitting layer of growing on N layer: multiple quantum well layer is the In that 9 repetition periods and thickness are respectively 3nm thickness _0.2ga _0.8the Al that N trap and 12nm are thick _0.51ga _0.18in _0.31n builds.Growth In _0.2ga _0.8during N trap layer, keep MOCVD reaction chamber temperature to arrive to 760 ℃, pressure 200Torr closes TMAl source simultaneously; Growth Al _0.51ga _0.18in _0.31when N builds, change reaction temperature to 860 ℃, pressure 350Torr;

5) regulate the temperature in MOCVD reative cell to remain on 860 ℃, pressure 350Torr, on multiple quantum well light emitting layer, growing P-type doped layer is Al _0.51ga _0.18in _0.31n, thickness is 200nm, Mg doping content is 5 * 10 ¹⁹cm ^-3; 6) by above-mentioned steps 5) product that obtains is placed in the 20min that anneals under the nitrogen atmosphere of 720 ℃.

Embodiment 3

A LED epitaxial structure for Lattice Matching, comprises on substrate layer 1 it being that thickness is the Al of 25nm successively _0.63ga _0.09in _0.28n nucleating layer 2, thickness are the not doped with Al of 1.2 μ m _0.63ga _0.09in _0.28n layer 3, thickness are the Si doped with Al of 1.5 μ m _0.63ga _0.09in _0.28the Mg doped with Al that N layer 4, multiple quantum well light emitting layer 5 and thickness are 200nm _0.63ga _0.09in _0.28n layer 6; Described multiple quantum well light emitting layer 5 is that 9 repetition periods and thickness are respectively the In that 3nm is thick _0.15ga _0.85the Al that N trap layer and 12nm are thick _0.63ga _0.09in _0.28n builds layer and forms; The Si doped with Al of 1.5 described μ m _0.63ga _0.09in _0.28n layer 4 is that the low doped layer by the heavily doped layer of 1.3 μ m and 0.2 μ m forms, and the Si doping content of heavily doped layer is 8 * 10 ¹⁸cm ^-3, the Si doping content of low doped layer is 2 * 10 ¹⁷cm ^-3.

Embodiment 4

The preparation method of LED structure described in embodiment 3, concrete steps are as follows:

1, Sapphire Substrate is placed under hydrogen atmosphere, is heated to 1080 ℃ and keep 5min, to remove the H of substrate surface ₂o and O ₂;

2, under hydrogen atmosphere condition, regulate temperature that substrate layer is heated to 540 ℃, pressure 500Torr, keeps 5min, take TMGa as Ga source, take NH3 as N source, take TMAl as Al source, take TMIn as In source, starts the Al that grows _0.63ga _0.09in _0.28n nucleating layer, thickness is 30nm; Then regulate the temperature to 860 ℃ in MOCVD reative cell, keep 10min, make described Al _0.63ga _0.09in _0.28n nucleating layer carries out recrystallization;

3) keep the temperature to 860 ℃ in MOCVD reative cell, pressure 350Torr, unadulterated Al grows _0.63ga _0.09in _0.28the Al of N layer 1.2 μ m, N-shaped doping _0.63ga _0.09in _0.28n layer 1.5 μ m.The Al that wherein N-shaped adulterates _0.63ga _0.09in _0.28n layer portions, the Si doping content of first growing is 8 * 10 ¹⁸cm ^-3the thick heavily doped layer of 1.3 μ m, rear growth Si doping content is 2 * 10 ¹⁷cm ^-3the thick low doped layer of 0.2 μ m;

4) Al adulterating at N-shaped _0.63ga _0.09in _0.28the multiple quantum well light emitting layer of growing on N layer: multiple quantum well layer is the In that 9 repetition periods and thickness are respectively 3nm thickness _0.15ga _0.85the Al that N trap and 12nm are thick _0.63ga _0.09in _0.28n builds.Growth In _0.15ga _0.85during N trap layer, keep MOCVD reaction chamber temperature to arrive to 760 ℃, pressure 200Torr closes TMAl source simultaneously; Growth Al _0.63ga _0.09in _0.28when N builds, change reaction temperature to 860 ℃, pressure 350Torr; 5) regulate the temperature in MOCVD reative cell to remain on 860 ℃, pressure 350Torr, on multiple quantum well light emitting layer, growing P-type doped layer is Al _0.63ga _0.09in _0.28n, thickness is 200nm, Mg doping content is 5 * 10 ¹⁹cm ^-3; 6) by above-mentioned steps 5) product that obtains is placed in the 20min that anneals under the nitrogen atmosphere of 720 ℃.

The foregoing is only embodiments of the invention, be not limited to the present invention.The present invention can have various suitable changes and variation.All any modifications of doing within the spirit and principles in the present invention, be equal to replacement, improvement etc., within protection scope of the present invention all should be included in.

Claims (8)

1. a LED epitaxial structure for Lattice Matching, is characterized in that, comprising: substrate, on described substrate, is disposed with Al from the bottom to top _xga _1-x-yin _yn nucleating layer, unadulterated Al _xga _1-x-yin _ythe Al of N layer, N-shaped doping _xga _1-x-yin _yn layer, In _aga _1-an trap layer and Al _xga _1-x-yin _yn builds the multiple quantum well light emitting layer of layer formation and the Al of p-type doping _xga _1-x-yin _yn layer; The Al of each layer _xga _1-x-yin _ythe trap layer In of the lattice constant of N and multiple quantum well light emitting layer _aga _1-athe lattice constant of N is identical, the Al of each layer _xga _1-x-yin _ythe band gap width of N is greater than the trap layer In of multiple quantum well light emitting layer _aga _1-athe band gap width of N.

2. LED epitaxial structure according to claim 1, is characterized in that, described nucleating layer is Al _xga _1-x-yin _yn, its thickness is 30nm-50nm, x span: 0.5≤x≤0.65, y span: 0.2≤y≤0.4.

3. LED epitaxial structure according to claim 1, is characterized in that, the described Al that is not doped to _xga _1-x-yin _yn, its thickness is 1 μ m-2.5 μ m, x span: 0.5≤x≤0.65, y span: 0.2≤y≤0.4.

4. LED epitaxial structure according to claim 1, is characterized in that, described N-shaped doped layer is Al _xga _1-x-yin _yn, its thickness is 1 μ m-2.5 μ m, x span: 0.5≤x≤0.65, y span: 0.2≤y≤0.4.

5. LED epitaxial structure according to claim 1, is characterized in that, the Al of described N-shaped doping _xga _1-x-yin _yn layer consists of high doped regions two parts, the heavily doped layer of the 1 μ m-2.2 μ m that first grows, and the low doped layer of rear growth 0.1 μ m-0.3 μ m, the Si doping content of heavily doped layer is 8 * 10 ¹⁸cm ^-3-2 * 10 ¹⁹cm ^-3, the Si doping content of low doped layer is 1 * 10 ¹⁷cm ^-3-3 * 10 ¹⁷cm ^-3.

6. LED epitaxial structure according to claim 1, is characterized in that, described multiple quantum well light emitting layer is by the spaced apart In in 1-15 cycle _aga _1-an trap layer and Al _xga _1-x-yin _yn builds the stacked composition that adds; Its gross thickness is 10nm-300nm; A span: 0.1≤a≤0.25, x span: 0.5≤x≤0.65, y span: 0.2≤y≤0.4.

7. LED epitaxial structure according to claim 1, is characterized in that, described P type doped layer is Al _xga _1-x-yin _yn, its thickness is 100nm-250nm, x span: 0.5≤x≤0.65, y span: 0.2≤y≤0.4.

8. according to a preparation method for the LED epitaxial structure described in claim 1-7 any one, it is characterized in that, concrete steps are as follows:

1) Sapphire Substrate is placed under hydrogen atmosphere, is heated to 1050 ℃-1150 ℃ and keep 5min, to remove the H of substrate surface ₂o and O ₂;

2) under hydrogen atmosphere condition, regulate temperature that substrate layer is heated to 450 ℃-600 ℃, pressure 100Torr-500Torr, keeps 5min-10min, take TMGa as Ga source, take NH3 as N source, take TMAl as Al source, take TMIn as In source, starts the Al that grows _xga _1-x-yin _yn nucleating layer, thickness is 30nm-50nm; Then regulate temperature to 750 in MOCVD reative cell ℃-860 ℃, pressure 100Torr-500Torr, keeps 5min-10min, makes described Al _xga _1-x-yin _yn nucleating layer recrystallization; Then regulate temperature to 750 in MOCVD reative cell ℃-860 ℃, pressure 100Torr-500Torr, unadulterated Al grows _xga _1-x-yin _ythe Al of N layer 1 μ m-2.5 μ m, N-shaped doping _xga _1-x-yin _yn layer 1 μ m-2.5 μ m;

3) Al of described N-shaped doping _xga _1-x-yin _yn layer consists of high doped regions two parts, the heavily doped layer of the 1 μ m-2.2 μ m that first grows, and the low doped layer of rear growth 0.1 μ m-0.3 μ m, the Si doping content of heavily doped layer is 8 * 10 ¹⁸cm ^-3-2 * 10 ¹⁹cm ^-3, the Si doping content of low doped layer is 1 * 10 ¹⁷cm ^-3-3 * 10 ¹⁷cm ^-3;

4) Al adulterating at N-shaped _xga _1-x-yin _ythe multiple quantum well light emitting layer of growing on N layer: multiple quantum well layer is InGaN trap and the thick Al of 8nm-20nm that 1-15 repetition period and thickness are respectively 2nm-10nm thickness _xga _1-x-yin _yn builds; Growth Al _xga _1-x-yin _ythe preparation condition that N builds is that the temperature in MOCVD reative cell is adjusted to 750 ℃-860 ℃, and pressure 100Torr-500Torr, take TMGa as Ga source, with NH ₃for N source, take TMAl as Al source, take TMIn as In source, growth Al _xga _1-x-yin _yn builds layer; Growth In _aga _1-athe preparation condition of N trap layer is that the temperature in MOCVD reative cell is adjusted to 750 ℃-860 ℃, and pressure 100Torr-500Torr closes TMAl source simultaneously, take TMGa as Ga source, with NH ₃for N source,, take TMIn as In source, growth In _aga _1-an trap layer;

5) regulate temperature to 750 in MOCVD reative cell ℃-860 ℃, growing p-type doped layer Al on multiple quantum well light emitting layer _xga _1-x-yin _yn, thickness is 100nm-300nm, Mg doping content is 5 * 10 ¹⁹cm ^-3--1 * 10 ²⁰cm ^-3;

6) by above-mentioned steps 5) product that obtains is placed in the 15min-30min that anneals under the nitrogen atmosphere of 650 ℃-750 ℃.